The present invention relates to specific types of pesticidal formulations which are emulsions in water (hereinafter referred to as EW formulations). The present invention particularly relates to EW pesticidal formulations containing the methyl ester of rosin their preparation and their application to pesticides having low or medium melting points.
Solid pesticides having a low or medium melting point are generally commercialized as emulsifiable concentrate solutions. However, such formulations require considerable quantities of organic solvents and other ingredients, creating toxicological and ecotoxicological problems. Thus, the United States Environmental protection Agency has recently begun a review of the ingredients of pesticidal formulations other than the active ingredient. In Europe, the EEC Council is in an advanced stage of legislating into law volatile organic compounds (VOC) and to require the eco-labeling of formulations which contain such VOC's. Indeed, Canada and Germany already have a system of ecotoxic labelling.
Rosin and its derivatives have been known since ancient times and they have found safe uses for a wide variety of products, including food and cosmetics. Uses in agriculture are also known as follows.
Great Britain patent no. 1,044,663 describes the use of a rosin or its derivatives in organophosphorous insecticidal compositions, but said compositions require the use of organic solvents.
Great Britain patent number 1,382,894 describes the use of rosin or its derivatives in carbamic ester compositions, but said compositions also require the use of organic solvents. The same can be said for the compositions described in Great Britain patent number 1,051,360 (Chemical Abstracts, 66: 54559v) and Soviet Union patent number 733,596 (Chemical Abstracts, 93: 127147d).
Rosin or its derivatives have been reported to be a tackifier agent in pesticidal formulations, such as in Great Britain patent number 1,398,227; U.S. Pat. No. 4,211,566; and Soviet Union patent number 1,187,773 (Chemical Abstracts, 104: 10445a). In addition, rosin or its derivatives have also been reported in pesticidal powder formulations. Examples are: Japan Patent Kokai Publication number 76/19,132 (Chemical Abstracts, 84: 175194c);
Japan Patent Kokai Publication number 63/250,308 (Chemical Abstracts, 111: 92336a); and Chinese patent publication number 1,031,467 (Chemical Abstracts, 113: 19497r).
Rosin derivatives have been reported to improve the fungal resistance of polymers in Chemical Abstracts, 86: 156376p.
European patent publication numbers 432,061 and 432,062 recently disclosed aqueous emulsions of a large variety of agrochemicals. However, said compositions did not require the use of rosin and still required the use of undesirable organic solvents.
U.S. Pat. No. 2,291,205 describes a formulation of a liquid pesticide (pine oil) using a metal salt of rosin for a liquid active ingredient and not a solid one. What works well for a liquid pesticide may not necessarily work for a solid pesticide in an EW formulation.
U.S. Pat. No. 2,490,925 describes a formulation where the rosin or rosin derivative is the active pesticide. In the present invention the rosin is used as a plasticizer. Thus, U.S. Pat. No. 2,490,925 is not relevant to the present invention.
U.S. Pat. No. 4,957,533 describes the use of--among a large number of compounds--rosin derivatives as solvents to formulations of a special group of compounds. But this patent does not exemplify a single case where rosin derivatives are used.
PCT Patent Number WO91/17,657 describes formulations of various pesticides using rosin as a plasticizer. However, most of the examples also use aromatic solvents. Only the examples with chlorpyrifos are relevant to the present inventions; and these examples are problematic. In Example K, if one increases the concentration of chlorpyrifos to the commercially useful concentration of 18-20%, will not work as there will then be no place for water. Example L also does not work as the use of 20% chlorpyrifos causes crystallization (as shown in the comparative Examples.